Mine is an Asus RT-AC88U.
I know it’s splitting hairs, but I don’t think it’s a disconnection issue: I believe it is a *reconnection* issue. That is, connection interruptions can happen for all sorts of reasons – for example, I’ve rebooted my router three times in the past week for other reasons – and in each case the OpenSprinkler has re-established the connection just fine as soon as the router comes back up. However, when the failure arises, the display on the OpenSprinkler shows that it is reconnecting, but it fails to do so until I intervene, no matter how long it is left to attempt reconnection. When the failure occurs, the issue is resolved immediately – and 100% reliably – by rebooting the OpenSprinkler unit. That appears to be the only way to resolve the issue. It would be good if detailed diagnostic logs were kept on the OpenSprinkler itself so that we can see what is going wrong in the OS’s system when it fails, but I am not aware of any logs except those associated with the timing of watering.